Fuel efficiency improvements for vehicles take several forms. On consideration is the activity included in the operation vehicle, including whether a driver operates a vehicle aggressively or conservatively, the rate of velocity, acceleration characteristics, and the like. Another aspect relate to the vehicle, including the vehicle weight and energy to move from a stopped position, to the resistance with which the wheels turn, the aerodynamics of the vehicle, the vehicle frontal area profile, etc. With respect to aerodynamics, the vehicle drag coefficient contributes to the power demand. Different surfaces and/or accessories affect a vehicle's baseline drag coefficient. Accordingly, though the vehicle fuel efficiency is optimized for a baseline operation, changes to the area may affect consumption by too much or too little fuel to operate the vehicle. It is desirable to adjust a vehicle fuel efficiency based on an altered vehicle surface area.